(9 12/25-8 16/25) +4 17/25

(9 12/25-8 16/25) +4 17/25= 5 4/25
1)9 12/25-8 16/25=1 12/25-16/25=28/25-16/25=12/25
2) 12/25 +4 17/25=4 29/25=5 4/25

будет5целых4/25:-) :-) :-) :-) :-) :-) :-) :-)